The lobby of the Grand Hyatt Washington looks as if it belongs in a resort rather than in the middle of the District. Howard Fields is partly responsible for that.

Fields is the designer and engineer for the 27,000-gallon lagoon and nine waterfalls that are the $1 million centerpiece of the hotel's 12-story atrium that extends from 35 feet above street level to 75 feet below ground.

Fields, 39, is not exactly an average guy. With a degree in biochemistry and having done graduate work in medicine at the University of California, he went into the most logical profession -- prune farming and pig ranching in Sonoma County, Calif.

He learned about pools and waterworks in 1979 when the city fathers of Healdsburg, Calif., decided they wanted a municipal pool, and he learned how to build it. He then designed more than 20 pools in the state and moved on to more exotic water designs -- including the world's longest swimming pool, at the Hyatt Regency Cerromar Beach Hotel in Puerto Rico, which includes a series of fountains, connected pools, waterfalls and slides.

Last year, Howard Fields & Associates, a group of about 15 architects, landscapers and engineers who create specialty water effects, had sales of about $50 million, according to Fields. He likes to think his projects will someday approach the elegance of the fountains of Spain, France and Italy.

In town last week to check the final preparations for the waterfalls, lagoon and fountains that dominate the lobby of the Grand Hyatt, Fields, who travels 500,000 miles a year to work on water projects, was effusive about the types of projects that many hotels, and even office buildings, are now using as part of their landscaping or recreational facilities. They include the Westin Hotel in Hawaii, where a fantasyland of 45 marble turtles, double life-size marble horses and dragons -- all spewing water -- will romp through a two-acre pool.

At some hotels, millions are being spent on such projects, perhaps because, as Hyatt Hotels President Darryl Hartley-Leonard says: "What the world does not need is another hotel . . . but it does need something that will make people open their eyes wide."

If Fields has anything to do with it, there will be plenty of wide-eyed customers at hotels around the country where his work is involved.